<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <link rel="stylesheet" href="./iconfont/iconfont.css">
    <style>
      .warp{
          width: 100%;
          height: 100vh;
          background-color: aqua;
      }
      .head{
          width: 100%;
          height: 40px;
          background-color: aqua;
      }
      .conent{
          width: 100%;
          height: calc( 100% - 40px );
          background-color: crimson;
          border-top-right-radius: 45px;
          border-top-left-radius: 45px;
      }
    </style>
<body>
   <div class="warp">
       <div class="head">
        123
       </div>
       <div class="conent">
        456 
       </div>
   </div>
   
</body>
</html>